Bicycle



' (No Model.)

P. R. BIGELOW.

BICYCLE.

No. 453,540. Patented June 2,1891.

IN VE N 7'01? 033 A TTOHNEYS' Ni'rnn STATES PATENT OFFICE.

FRANK R. BIGELOXV, OF GLOUCESTER CITY, NE\V JERSEY.

BICYCLE.

srncrmca-rmn forming part of Letters Patent No. 453,540, dated June2,1891.

Application filed January 30,1891. Serial No. 379,652. (No model.)

To all whom it may concern:

Be it known that I, FRANK R. BIGELOW, of Gloucester City, in the countyof Camden and State of New Jersey, have invented a new and ImprovedDifferential Gear for Bicycles, of which the following is a full, clear,and exact description.

My invention relates to improvements in a diiferential gear for bicyclesor other kinds of velocipedes; and the object of my invention is toproduce a simple and efficient device by means of which a bicycle-gearmay be quickly changed, so that the bicycle may be driven rapidly wherethe road is easy, or it may be changed to give more power and less speedwhere the road is loose or hilly.

To this end my invention consists in certain features of constructionand combinations of parts,which will be hereinafterdescribed andclaimed.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure 1 is a broken sectional View showing the device applied to thetreadle-shaft of a bycicle. Fig. 2 is a broken end view of the same.Fig. 3 is a detail sectional view of the thumb-screw by which the deviceis adjusted. Fig. 4 is a detailend view, partly in section, showingtheconstruction of thetoothedsleeve and Fig. 5 is a detail diagrammaticview showing the manner in which the gear is connected to thesprocket-wheel of a bicycle.

A represents the bearing of the treadleshaft, which is supported byanarm A in the usual manner, and through which extends longitudinally thetreadle-shaft B, which has a crank 13' at each end, and the shaft isturned by means of the cranks in the ordinary way.

Mounted loosely on the treadle-shaft B at opposite ends of the bearing Aare the sprocket-wheels G and C, the sprocket-wheel C being considerablylarger than the other sprocket-wheel, whereby the speed of the machinewill be fast or slow, accordingly as the power is taken from thelargerwheel 0 or the smaller one 0. Each of the sprocket-wheels has on itsinner side, at a point adjacent to the shaft B, a series of sockets c,which receive the teeth on the sliding sleeve, as described below, andenable the sprocket-wheels to be driven.

lVit-hin the bearing A is a sleeve D, which corresponds in length to thelength of the hub, and which is held to slide on the shaft B. Near thecenter of the sleeve D is a 1011- gitudinal slot D, through whichextends a pin 1), secured to the shaft B, so that the sleeve ispermitted to slide on the shaft, but the pin causes the sleeve to turnwith the shaft. The sleeve D has a series of recesses cl at each end,thus forming projecting teeth cl',\vhich teeth are shaped to fit thesocketsc in the sprocketwheels C and C, so that by sliding the sleeveand bringing the teeth into engagement with the sockets of one of thesprocket-wheels that sprocket-wheel will be driven when the shaft B isturned.

A hollow thumb'screw E is mounted loosely on the shaft B and extendsthrough the sprocket-wheel G into the end of the sleeve D, which iscounterbored to receive it. The inner end of the thumb-screw isexternally threaded, as best shown in Fig. 1, and the sleeve D isinternally threaded, as shown at d, to fit the thread of thethumb-screw. The outer end .of the thumb-screw is provided with ahandle-disk E, so that it maybe conveniently turned, and by screwing thethumb-screw out or in the sleeve D may be moved and caused to engage oneof the sprocket-wheels. It is obvious that the thumb screw may bearranged at either end of the hub A, and that either end of the sleeve Dmay be screwthreaded to receive it.

In Fig. 5 I have shown in dotted lines a detail view showing the mannerin which the gear is connected with a bicycle-wheel, and as there aretwo sprocket-wheels there must be two sprocket-wheels on thebicycle-wheel, one on each side, and these are preferably made ofdiiterent sizes, the larger F connecting by a chain H with the smallersprocketwheel 0 and the smaller wheel F on the main bicycle-wheelconnecting by a similar chain with the larger of the treadle-sprocketsC. It will thus be seen that by shifting the sleeve D,'which serves as aclutch, either of the sprocket-wheels may be driven and the bicycle maybe propelled with great power and at moderate speed, or, if the road iseasy, it may be driven with great velocity.

I have shown the gear mechanism in connection with a treadle-shaft whichis suspended by an arm, and which is specially intended for use onSafety bicycles; but it is obvious that the same mechanism may beapplied to the hub of a bicycle-wheel, if desired.

When the machine is to be driven rapidly, the sleeve D is made to engagethe sprocketwheel 0, so that that Wheel servesas a driving-Wheel, and ifthe machine is to be driven slower, but with greater power, the sleeveis connected with the smaller sprocket-wheel.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. A differential gear for bicycles, comprisin g atreadle-shaft, sprocket-Wheels of dilterturn with the shaft and havingteeth at each end, said sleeve having also an internal screw- 7 thread,and a hollowthumb-screw mounted on the shaft and adapted to engage thethread of the sleeve, substantially as described.

FRANK R. BIGELOW. lVitnesses:

R0131. J. RoLsToN, HARLAN S. MINER.

